/Engine/Source/Runtime/Engine/Public/Slate/SceneViewport.h
Called on a touchpad gesture event
virtual [FReply](API\Runtime\SlateCore\Input\FReply) OnTouchGesture ( const [FGeometry](API\Runtime\SlateCore\Layout\FGeometry) & MyGeometry, const [FPointerEvent](API\Runtime\SlateCore\Input\FPointerEvent) & InGestureEvent )